Androgen blockade therapy has become the mainstay for advanced prostate cancer. However, prolonged androgen blockade leads to outgrowth of androgen independent (AI) cells and the development of castration resistant prostate cancer (CRPC). The transition to androgen independence can occur through several adaptive mechanisms and usually results in the acquisition of a more aggressive phenotype, compared to their androgen sensitive progenitors. However, methods are needed for accurate and early diagnose of these aggressive tumors so appropriate treatments can be selected.